This invention relates to resinous compositions free of the dioxin hazards or to thermoplastic resin compositions containing no halogen element, whose utility lies in achieving the commercial value of vinyl chloride resin or its compound. Particularly, this invention substantially relates to new resinous compositions comprising an olefin resin, and a styrene-acrylonitrile based resin with incorporation of an epoxy group-containing resin as third component, and to improved sheet products therefrom.
Vinyl chloride resin has found a large market for the value of its popular price as well as technically its good compatibility with plasticizers (DOP, DBP) and hence has extended the products to wide range, from hard manufactures to soft articles. For instance, vinyl chloride products have prevailed in such end uses as: toys, stationary articles, rain protection wearings, ornamental coverings, in the personal as well as household article field, and industrially the covering for applications in car interior fittings; panels, cushions, further in general packaging or wrapping purposes. Of them, one strong market has lain in sheet products, because the vinyl chloride sheet or film is well suited to processing by the high frequency (HF) welding machines. However, such largely grown market has caused environmental problems because of inclusion of chlorine, a kind of halogen elements, such as heavy damage or corrosion to the incineration apparatus in the recycling process of vinyl chloride products and environmentally the generation of dioxin, harmful substance. Thus, industrially there has been desired the advent of a substitution for vinyl chloride products or something else which is free of halogen element and well suited to the HF welding.
Attempts intended to find a resinous composition provided with the freeness of vinyl chloride component as well as the suitability to the HF welding were made in a patent application (Japanese Unexamined Patent Publication Hei 6-80838), wherein an olefin resin was blended with an ethylene-ethyl acrylate-maleic anhydride copolymer, and in another patent application (Japanese Unexamined Patent Publication Hei 8-302144), wherein an olefin resin was blended with an acrylonitrile-styrene copolymer. However, such prior attempts resulted in so poor or inferior compatibility and hence the HF welder suitability, moldability, as well as appearance of sheet products were not commercially acceptable.
One aspect of this invention relates to resinous compositions whose features are:
(Comp. A) a thermoplastic olefin resin accounting for 99 to 1 wt. parts,
(Comp. B) an acrylonitrile-styrene-alkyl acrylate copolymer accounting for 1 to 99 wt. parts,
based on 100 wt. parts of Comp. (A+B), to which an epoxy resin (Comp. C) is mixed as a third component into the composition in a range of 1 to 100 wt. parts based on 100 wt parts of (A+B).
Another aspect of this invention relates to sheet products manufactured from the resinous compositions as noted above, whose features lie in well suitability to the HF welding, moldability, as well as commercially acceptable appearance.
The blend ratios as noted above between the components A, B, and C are determined by experimental findings, wherein in the case of sheet products, preferred conditions are such that in the system A+B, A accounts for more than 50%, and in the system C+(A+B), (A+B) accounts for more than 50%. In addition to such resin blend, other functional agents or chemicals such as antioxidant, UV absorber, pigment, filler are to be blended according to the end use or technical requirements or general knowledge in the art.
Sheet products in this invention include various product forms such as sheet proper, laminate with another substrate, foamed sheet.